Intra-flow interference is interference between intermediate routers sharing the same flow path.
For wireless transmission from S1 to D1, either S1-X1 and X2-D1, or X1-X2, can operate at any given time slot to avoid intra-flow interference between the links.
Application
In wireless routing, routing protocol WCETT,[1] MIC[2] and iAWARE[3] incorporate consideration to the intra-flow interference metric.
A. P. Subramanian, M. M. Buddhikot, and S. C. Miller, “Interference Aware Routing in Multi-Radio Wireless Mesh Networks,” IEEE Workshop Wireless Mesh Networks, September 2006, pp. 55–63.